LinuxQuestions.org
Go Job Hunting at the LQ Job Marketplace
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 04-19-2013, 03:43 AM   #1
raghavsood999
LQ Newbie
 
Registered: Sep 2012
Posts: 9

Rep: Reputation: Disabled
Determining user processes and CPU/MEM INFO information?


Ok, this is a question i got in test and bought it here for some smart person to answere. Please explain why This would be the best answere:


This is a snapshot of what the system gave to me as result of the
TOP command in the red hat enterprise linx command line.

::::::::::::::::::::::::::::::::::::::::::::::::::::::
top - 05:14:52 up 3 days, 12:34, 2 users, load average: 4.39, 1.40, 0.48
Tasks: 86 total, 79 sleeping, 7 running, 0 zombie, 0 stopped
Cpu(s): 20.0%us, 79.8%sy, 0.4%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 255184k total, 247244k used, 7940k free, 91620k buffers
Swap: 521632k total, 20756k used, 500876k free, 67012k cached
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Q1. Roughly how much physical memory is being devoted to processes, in megabytes?
A. 255 - 92 = 163
B. 255 - 8 = 247
C. 255 - 67 = 188
D. 255 - 92 = 163
E. 255 - 8 - (92 + 67) = 88
The answere is actually E, BUT WHY IS IT E?



Question 2:
Roughly what percentage of the machine's physical memory is devoted to caching I/O operations?
A. 5%
B. 10%
C. 25%
D. 33%
E. 60%
the correct one is E but why is it 60 percent?
:::::::::::::::::::::::::::::::::::::::::::::::::::;;;;;
root@station root]$ uptime
05:06:00 up 3 days, 12:25, 2 users, load average: 0.89, 3.25, 8.87
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Refer to the information on the top using the command uptime.


question 1:
Which of the following best describes the activity of the machine?
A. The machine has recently been active, but is currently inactive.
B. The machine has recently been inactive, but is currently active.
C. The machine has been and continues to be active.
D. The machine has been and continues to be inactive.
E. None of the above
The correct one is A. buut why?


The last on also refers to the exhibit listed above.


Questions 2.:


2.

How long has passed since the machine was most recently booted?
A. 5 hours
B. 8.87 hours
C. 12 hours
D. 2 hours
E. 84 hours
The correct one is E why?

How can it be 84 hourse if every thing is in minutes. It has been up for 3 days? well thats 3 times 24 right? so that is equal to 72 hourse for 3 days. The machine has been running since then so why is this last question E say 84 instad of 72?
 
Old 04-19-2013, 05:45 AM   #2
chrism01
LQ Guru
 
Registered: Aug 2004
Location: Sydney
Distribution: Centos 6.6, Centos 5.10
Posts: 16,473

Rep: Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125
uptime: its all the fields until a new field name (users) appears....
Code:
 up 3 days, 12:34,
BTW, please use code tags when posting tech info https://www.linuxquestions.org/quest...do=bbcode#code
 
Old 04-20-2013, 02:50 AM   #3
raghavsood999
LQ Newbie
 
Registered: Sep 2012
Posts: 9

Original Poster
Rep: Reputation: Disabled
hey questions regards to UPTIME COMMAND

hello, as i said i know what the uptime command does.
I just want to know why the ansere of one of the questions i 84 hourse. The one where it asks the user:


how long has it been since the machine has last booted?


also this one:

What type of work is the machine doing? looking at the users, cpu timing and it's percentages how would we identify if the system is performinh numerous calculations or performing many input and out put tasks or both? It's by looking at the users? cpu or meminfo?
Thanks in advnace
Raaghav./
 
Old 04-20-2013, 07:20 AM   #4
johnsfine
LQ Guru
 
Registered: Dec 2007
Distribution: Centos
Posts: 5,272

Rep: Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163
Quote:
Originally Posted by raghavsood999 View Post
Q1.
...
The answere is actually E, BUT WHY IS IT E?
Free memory (8) is not "devoted to processes". Depending on your point of view buffers+cache (92+67) is either mostly not or entirely not "devoted to processes".
So given that limited data, the amount devoted to processes is the total minus the specific parts of that total which are disjoint and not devoted to processes.

Did you think some answer other than E was correct? If so, why?
Quote:
Question 2: ... why is it 60 percent?
Caching I/O is most of buffers plus most of cache. Those add up to 62% of the total. Since it is a multiple guess (not free response) quiz, you select 60%.

Quote:
Which of the following best describes the activity of the machine?
The 20%us and 79.8%sy shows the CPU is completely in use at the moment.

I think the load average info is typically bogus anyway and I forget what units it is in. So possible something about past activity can be deduced from that, which I am missing. So far as I understand, it measures some process queuing information that doesn't actually correlate well with any sensible definition of usage level.

Quote:
how would we identify if the system is performinh numerous calculations or performing many input and out put tasks or both?
The 79.8%sy stands out as the unusual and key factor in that question. But what exactly it means is less clear.

Obviously it indicates the CPU usage is not dominated by user mode calculations. It is dominated by kernel work. We can assume that kernel work is in response to use mode requests. But within that, there are too many possibilities.

One possibility is that the user mode processes are making a lot of I/O requests that are being almost all satisfied from buffers/cache so the CPU is never stalled waiting for physical I/O.

Last edited by johnsfine; 04-20-2013 at 07:30 AM.
 
Old 04-20-2013, 07:36 AM   #5
johnsfine
LQ Guru
 
Registered: Dec 2007
Distribution: Centos
Posts: 5,272

Rep: Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163
Quote:
Originally Posted by raghavsood999 View Post
as i said i know what the uptime command does.
I just want to know why the ansere of one of the questions i 84 hourse.
At least pretend to be willing to put some thought or effort into this.

Look at the answer you were given, that you seem to be rejecting. It is the answer to your question. Think about what chrism01 said until you understand how it is your answer.
 
Old 04-21-2013, 01:18 AM   #6
raghavsood999
LQ Newbie
 
Registered: Sep 2012
Posts: 9

Original Poster
Rep: Reputation: Disabled
Hey reply

hello thanks people for hhelp. now i undertsand .

no worries!
you may cloe this thread?
 
Old 04-21-2013, 02:40 PM   #7
colucix
Moderator
 
Registered: Sep 2003
Location: Bologna
Distribution: CentOS 6.5 OpenSuSE 12.3
Posts: 10,509

Rep: Reputation: 1965Reputation: 1965Reputation: 1965Reputation: 1965Reputation: 1965Reputation: 1965Reputation: 1965Reputation: 1965Reputation: 1965Reputation: 1965Reputation: 1965
Quote:
Originally Posted by raghavsood999 View Post
you may cloe this thread?
Nope. If you're happy with the answers given to your questions, you can mark the thread as SOLVED (see at the top of your first post). On the other hand threads at LinuxQuestions stay open to let other users post their add-on (if any).
 
Old 04-26-2013, 04:54 AM   #8
raghavsood999
LQ Newbie
 
Registered: Sep 2012
Posts: 9

Original Poster
Rep: Reputation: Disabled
Quote:
Originally Posted by chrism01 View Post
uptime: its all the fields until a new field name (users) appears....
Code:
 up 3 days, 12:34,
BTW, please use code tags when posting tech info https://www.linuxquestions.org/quest...do=bbcode#code

Ok listen as you said the following about uptime command in linux:

Code:
 up 3 days, 12:34,
Why is that equal to 84 hours. Iv treid this adding 24*3 because there is 24 hourse in a day and if it states there is 3 days then it should be 72 hourse altogether not 84 hours?
 
Old 04-26-2013, 05:06 AM   #9
chrism01
LQ Guru
 
Registered: Aug 2004
Location: Sydney
Distribution: Centos 6.6, Centos 5.10
Posts: 16,473

Rep: Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125Reputation: 2125
Quote:
uptime: its all the fields until a new field name (users) appears....
Read that carefully and it'll become clear
 
Old 04-26-2013, 06:26 AM   #10
johnsfine
LQ Guru
 
Registered: Dec 2007
Distribution: Centos
Posts: 5,272

Rep: Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163Reputation: 1163
Quote:
Originally Posted by raghavsood999 View Post
Code:
 up 3 days, 12:34,
Maybe we are being unfair to a non native speaker of English.

The word "plus" is implied when you say or write that in English.

"3 days, 12:34" means three days plus twelve hours plus thirty four minutes.

That is closer to 85 hours than to 84. But in a multiple guess test, it doesn't pay to over think such details.

Last edited by johnsfine; 04-26-2013 at 06:29 AM.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
processes/CPU Usage/Mem Usage desktop wallpaper ceantuco Linux - Newbie 2 04-13-2009 01:14 PM
possible HW list OC; by MoBo, CPU, Mem, BIOS CPU x Addition HCL (stock BIOS settings) digital8doug Linux - General 17 12-15-2006 07:01 PM
FC 3 - Determining IP information ... failed smaisnie Fedora 6 12-23-2004 12:30 PM
Determining IP information for eth1 nistelrooy Linux - Networking 1 11-25-2004 12:16 AM


All times are GMT -5. The time now is 02:50 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration